Answer:
87.5
Step-by-step explanation:
By completing the square,
y
=-14x^2+70x
=-14(x^2-5x)
=-14(x-5/2)^2+175/2
the max. height=175/2
i.e. 87.5
in the number line, the end points are DG, and the point in between is O
DG = 88
DO = 5x + 12
OG = 2x
Set the equation. The two parts (DO & OG) are equal to the whole (DG)
2x + 5x + 12 = 88
Simplify. Combine like terms
(2x + 5x) + 12 = 88
7x + 12 = 88
Isolate the x. Remember to do the opposite of PEMDAS. Subtract 12 from both sides
7x + 12 (-12) = 88 (-12)
7x = 76
Isolate the x. Divide 7 from both sides:
7x/7 = 76/7
x = 76/7
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Find DO. Plug in "76/7" for x:
DO = 5x + 12
DO = 5(76/7) + 12
Simplify. Remember to follow PEMDAS. Multiply 76 with 5
DO = 380/7 + 12
Next, divide 380 with 7
DO = 54.29 (rounded)
Finally, add
DO = 54.29 + 12
DO = 66.29
66.29 is your answer
hope this helps
You just divide the distance travelled by the time like so: 145mi/2.5h and get 58mph. You can convert the 145mi into meters and 2.5h into seconds (145mi is approximately 233345m; 2.5h is 9000 seconds) and get an approximate speed of 26m/s if you want to convert to SI units.
